Method for continuous dyeing of yarns

ABSTRACT

A method of continuously dyeing a yarn, which comprises, heating a running yarn to a temperature above the boiling point of a solvent in a dye and contacting said heated yarn with one or more dye applicators having a dye discharge aperture while discharging a dye through said aperture and onto said yarn is disclosed. An apparatus for continuously dyeing a yarn is also disclosed.

. United States Patent 1 1 1111 ,808,618 Arimoto et a1. May 7, 1974 METHOD FOR CONTINUOUS DYEING OF 1,934,796 11/1933 Friederich 68/200 x YARNS 2,106,311 1 1938 Whitehead... 8/l5l.2 2,428,284 9/1947 Krogel 8/15l.2 x [75] Inventors: Help Arunoto; Toku o Goto; Kumo 3,600,730 8/1971 Evans 8/149 Amemiya; Tunekatu Seki, all of K t Ja yo 0 pan Primary Examiner-Billy J. Wilhite [73] Assignee: Unitika Ltd., Amagasaki-shi, Japan Assistant p i R. Coe 22 Filed. June 14- 19'72 Attorney, Agent, or Firm-Sughrue, ROthWCii, M1011,

Zinn & Macpeak [21] App]. No.: 262,846

[30] Foreign Application Priority Data ABSTRACT June 14, Japan A method of continuously dyeing a yarn, comprises, heating a running yarn to a temperature above 2% g 41,2 32 the boiling point of a solvent in a dye and contacting i 5 2 2 said heated yarn with one or more dye applicators 1 0 care 68/200 6 having a dye discharge aperture while discharging a dye through said aperture and onto said yarn is disclosed. An apparatus for continuously dyeing a yarn is [56] eferences Cited also disclosed UNITED STATES PATENTS 1,65 l,l67 Alstyne et a1 68/200 10 Claims, 9 Drawing Figures SHEET 1 [IF 2 FIGI HGBB

HEB/l PATENTEDIMY 11w V 3.808.618

SHEET 2 BF 2 wlllululllllfll 1 METHOD FOR CONTINUOUS DYEING OF YARNS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a method for continuously dyeing various forms of yarns of synthetic fibers, natural fibers or a mixture of these fibers, such as filament yarns, spun yarns or crimped yarns, at high speed, and especially to a method and an apparatus suitable for dyeing these yarns in multicolors.

2. Description of the Prior Art It has previously been a wide spread practice to dye yarns in the form of skeins or packages such as cheese or cone in order to obtain uniform dyeing, and a number of apparatuses used for this dyeing are known. One of the prior methods of continuously dyeing yarns comprises dipping a yarn in a dye bath while passing it therethrough, removing the excess dye liquor from the yarn using nip rollers thereby to adhere a prescribed amount of the dye liquor to the surface of the yarn, and then heating the yarn to effect dye exhaustion. Another method involves bringing a yarn into contact with a revolving roller partly immersed in a dye bath to transfer the dye liquor on the roller to the yarn, and then heating the yarn. The former method has the disadvantage that the yarn tends to become flattenedwhen held by the nip rollers, and it is difficult and inefficient to revolve the nip rollers at high speed yet to squeeze the yarn uniformly. According to the latter method, the dye liquor is scattered when the roller for applying the dye is rotated at high speed, and therefore it is difficult to dye the yarn at high speed.

The methods generally known to dye intermittently colored yarns or multicolored yarns include, for examtermittent contact along its length with a revolving roller partly immersed in a dye bath to transfer the dye liquor intermittently to the yarn, followed by a heat-treatment" to effect dye exhaustion.

3. A method in which a running yarn is contacted intermittently with a mechanically operated dye applicator which is reciprocatingly moved over a small distance, thereby to transfer the dye liquor intermittently to the yarn, followed by a heattreatment to effect dye exhaustion.

4. A method in which a yarn is knitted, and a desired pattern is printed on the resulting knitted fabric. The fabric is then treated with steam or a dry heat to fix the dye then the fabric is deknitted.

. However, these methods have various disadvantages. In method 1 it is difficult to obtain a yarn having a dyed portion of a short length because of the necessity for immersing a part of the skein in a {dye bath, and moreover, the productivity of this method is low. According to method 2), the tension of the yarn becomes non-uniform, and yarn breakage tends to occur. Method 3) has the disadvantage that it is difficult to 0perate the dye applicator at high speed, and at high speed, the dye liquor scatters. According to method 4), fuzzes or fluffs tend to occur during the knitting and deknitting operations, and moreover, the productivity of this method is low.

. It is an object of this invention to provide a method for dyeing yarns, which is free from the above described disadvantages of the prior art.

It is another object of this invention to provide a method for continuously dyeing yarns in desired forms composed of various fibrous materials at very high speed.

It is still another object of this invention to provide a method for obtaining intermittently colored yarn or multicolored yarn.

SUMMARY OF THE INVENTION The present invention provides a method for continuously dyeing a yarn. The method comprises heating a running yarn to a temperature above the boiling point of a solvent in a dye and dyeing the yarn by contacting the yarn with one or more dyes discharged from one or more dye applicators having an aperture for discharging the 'dye.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS The invention will be described with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing one embodiment of this invention.

FIG. 2 is a perspective view of a dye applicator 5 shown in FIG. 1.

FIG. 3 is a view illustrating the use of two dye applicators, FIG. 3A showing their arrangement on opposite sides of the yarn, and FIG. 38 showing their arrangement on the same side of the yarn.

FIGS. 4 and 5 are sectional views of the yarns obtained by the method of this invention.

FIG. 6 is a side elevation of the yarns obtained by the method of this invention.

FIG. 7 is a sectional view of one embodiment of a means for discharging the flow of dye intermittently.

FIG. 8 is a sectional view of the principal parts of one dye applicator device from which three different dyes are discharged.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a yarn 2 is unwound from a cone 1, passed over a guide roller 3, heated by a heater 4, and then contacted with a dye applicator device 5. A dye is applied to the yarn 2 using this dye applicator 5. The dye is stored in a tank 6, and supplied to the dye applicator 5 by a metering pump 7. The dye is then discharged from a small aperture provided in the applicator 5. After application of the dye, the yarn 2 is dried in a dryer 8, passed over a guide roller 9, and is taken up on a winder 10.

The details of the dye applicator device 5 in FIG. 1 are shown in FIG. 2. In FIG. 2, the reference numeral 13 represents a U-shaped groove through which the yarn 2 runs in contact therewith. A dye discharge aperture 11 is provided near the central portion of the bottom of the U-shaped groove. The dye which is supplied through a pipe 12 is discharged from this aperture in the appropriate amount, and applied to the yarn 2 which is running through the groove 13 in contact with the bottom of the groove including the discharge aperture 11. The diameter of the dye discharge aperture and the opening angle of the U-shaped groove differ somewhat according to the thickness of the yarn to be dyed. Generally, however, it is desirable that the diameter of the discharge opening ranges from about 0.1 to lmm, and the opening angle of the groove through which the yarn passes ranges from about 15 to 145.

In FIG. 1, only one dye applicator device is shown. By providing two or more dye applicators, it is possible to dye a yarn with more than one color. The use of two applicators is illustrated in FIG. 3.

Referring to FIG. 3A, the running yarn 2 comes in contact with one of the dye applicators 5, and the dye is applied to one side of the yarn from the aperture 11. This yarn then comes in contact with the other applicator device disposed opposite to the applicator 5, and a dye the same color as or a dye a different color from that applied by the applicator 5 is applied to the opposite side of the yarn 2. When different dyes are applied, the yarn is dyed in two colors as shown sectionally in FIG. 4, and the two colors are separately continuous along the length of the resulting yarn. FIG. 3B illustrates the arrangement in which two dye applicator devices 5, 5' are provided on the same side of the running yarn, in which the same or different dyes can be applied to the yarn from the respective discharge apertures in the applicator devices. Likewise, when three applicator devices are provided around the yarn, the yarn can be dyed in three colors as shown in FIG. 5. When such a yarn is used for conventional knitting or weaving, torsion occurs in the yarn during the knitting or weaving process, andtherefore, a random colored fabric is obtained as a result of the weaving or knitting.

Various multicolored yarns as shown in FIG. 5, A, B and C can be obtained by changing the amount of the dye or the position of the dye applicator, as desired. FIG. 5A illustrates a section of a multicolored yarn obtained by discharging small amounts of the dye. FIG. 5B shows a section of a multicolored yarn in which two adjoining colors are mixed with each other as a result of discharging large quantities of the dye. FIG. 5C shows a section of a multicolored yarn which contains undyed portions as a result of arranging the dye applicators around the yarn at unequal intervals.

Whan a yarn is dyed using one or more of the dye applicators shown in FIG. 2, it is possible to obtain variously dyed yarns by changing the amount of the dye discharged. Thus, the yarn can be uniformly dyed similar to conventional dip dyeing, or it can be dyed randomly to obtain a yarn having intermittent dyed portions along its length, i.e., intermittently colored yarn or to obtain multicolored yarns. For example, when the dye is continuously discharged from the aperture of the dye applicator, it is possible to obtain a yarn having a continuous dye portion along its length as shown in FIG. 6A. If, on the other hand, the dye is fed intermittently and discharged, a yarn colored intermittently along its length can be obtained as shown in FIG. 6B. Any desired means can be employed to obtain an intermittent flow of the dye. One method involves the incorporation of air bubbles in the dye. For example, an air pump can be provided somewhere in the pipe for feeding the dye in order to introduce air bubbles thereinto. By changing the amount of air bubbles fed by the air pump, the distances between the colored portions can be varied as desired. In order to prepare very fine bubbles, a gas such as air or carbon dioxide gas is dissolved under pressure in the dye and the bubbles of these gasses may be generated in the dye in the vicinity of the discharge openings where the pressure approaches normal atmospheric pressure. Or these gases dissolved in the dye may be converted into bubbles by heating in the vicinity of the discharge openings. Alternatively, a chemical generating a gas upon heating, such as sodium bicarbonate, can be incorporated in the dye, and by heating it near the discharge openings, bubbles are generated.

The interruption in the flow of the dye can also be effected using an apparatus of the structure shown in FIG. 7. Referring to FIG. 7, a piston 22 is moved reciprocatingly in the direction of A by an electromagnet 21. When the electromagnet is inoperative, the piston 22 is held in contact with a dye liquor discharge opening 26 using a spring 23, thereby to stop the discharge of the dye liquor. The reference numeral 24 represents an inlet for the dye, and 25, an outlet for the dye. An electric wire is shown at 27. The flow of the dye which enters the apparatus through the inlet 24 and the outlet 25 is interrupted by actuating the electromagnet 21 intermittently thereby reciprocating the piston 22 and closing and opening 26 intermittently.

By discharging two or more dyes from one dye applicator device alternately or randomly using such an apparatus, there can be obtained a yarn which is dyed continuously or intermittently in two or more colors along the length, as shown in FIG. 8. Referring to FIG. 8, a yarn 31 runs in contact, with dye applicator device 32 which is shown in detail as reference numeral 5 in FIG. 2. From a discharge aperture 33, dyes a, b and c of different colors are continuously or discontinuously discharged at varying intervals, and applied to the yarn 31 repeatedly in any order of a, b and c, or in a random sequence. The dyes which have been fed into dye intermitting devices 34, 34 and 34" through delivery pipes 35, 35' and 35" are intermitted here, and discharged from the discharge opening alternately or in a random sequence, and thus applied to the yarn 31. At this point, the dyed portions may be rendered continuous; or discontinuous, that is, undyed portions may be formed.

In conventional pad-dyeing the yarn to which the dye has been applied is steamed or subjected to a dry heattreatment in the form of a package such as a cone or cheese, or in the form of a skein thereby to fix the dye to the fibers. However, the steaming method has the disadvantage that longer periods of steaming time are needed to achieve sufficient dyeing, and the efficiency is poor. The dry-heat-treatment has the advantage that the treatment can be completed within shorter periods of time but still poses the problem of the decomposition and sublimation of the dye because of the hightemperature treatment. Accordingly, in the present invention, the yarn is preheated to a temperature above the boiling point of a solvent in the dye prior to the application of the dye to the yarn, and then the dye, which can also be preheated if desired, is applied to the yarn, followed by a drying and a winding up of the yarn. This preheating of the yarn contributes to an activation of the molecular movement of the fibers, and the dye is applied to the yarn in the condition in which the internal structure of the fiber is relaxed. Thus, it is possible to dye the yarn instantaneously, and to dye at high speeds.

The heating temperature applied to the yarn prior to the application of the dye varies depending upon the type of the fiber but, usually, it is higher than the boiling point of the solvent employed in the dye and not higher than the point at which the physical and chemical properties of the yarn drastically change. The temperature of the dyes applied to the yarn is controlled within the range of 30C below the boiling point of the solvent of the dye up to its boiling point. For example, when water is used as a solvent for the dye, temperature of 70 to 100C are suitable. At a temperature below 70C., long periods of time are needed for drying, and it is impossible to dye the yarn at high speed.

The yarn to which the dye has been applied is dried by passage through a dryer, and wound up to complete the dyeing operation. Usually, the dyeing operation is completed at this point, and post-treatments such as washing or soaping are unnecessary. A great advantage of this invention is that the dyeing is completed in this state. Where a darker color and a high fastness are desired, the wound up yarn may further be steam set.

The yarns that can be dyed by the method of this invention may be any yarns, such as spun yarns, continuous filament yarns or crimped yarns, composed of natural fibers such as cotton, wool or silk, synthetic fibers such as polyester, acrylics, polyamides and the artificial cellulose fibers such as viscose rayon, cellulose acetate or mixtures of these fibers.

The dye to be used in this invention can be chosen according to its suitability for the fibers to be dyed. If desired, a swelling agent for the fibers, a carrier or a solvent may be added to the dye in order to achieve the objects of this invention more effectively.

The dyeing according to the method of this invention can be carried out at a speed as high as 500 to 1,500 meters per minute without changing the tension of a running yarn, irrespective of whether the yarn has a non-uniform thickness or whether it contains knots.

The present invention will be illustrated in greater detail by reference to the following Examples.

EXAMPLE 1 AMOUNT (parts by weight) DYE FORMULATION V Cl Acid Red 219 Ethyl Alcohol 400 Benzyl Alcohol 40 Water 510 EXAMPLE 2 A false-twisted nylon 6 yarn (l260den/80fil/3ply) was passed over through an apparatus of the type shown in FIG. 1 using aheater held at 200C and 0.1 cc each of the following three dyes A, B and C was in- DYE COMPONENT DYE FORMULATION (parts by weight) CI Acid Yellow 114 5 8 16 CI Acid Black 64 l 2 6 Benzyl Alcohol 60 60 60 Ethyl Alcohol 200 200 200 Water 734 730 718 EXAMPLE 3 A crimped nylon 6 yarn (840den/fil/2ply) was passed at a speed of 500 m/min. through an apparatus of the type shown in FIG. 1 using a heated plate held at 200C, and a dye of the following formulation was applied to the running yarn at a discharge rate of 20 cc/min. During transit of the dye through a discharge pipe, air was introduced using an air pump into the dye 100 times per minute to form bubles, whereby the discharging of the dye was intermittingly interrupted. After drying, the dyed yarn was wound up on a cheese. An intermittently dyed yarn of good fastness was obtained.

EXAMPLE 4 A polyester filament yarn (75den/24fil) was passed over a heater held at 210C at a speed of 700 m/min., and then the following dyes A, B and C were heated to C discharged each at a rate of 0.8 cc/min. from three dye applicator devices to apply them to the surface of the yarn. The yarn was then passed through a non-contact heater held at 150C, and wound up. The would-up cheese was formed into a skein, and steamed for five minutes at 140C. The surface of the yarn obtained was dyed three separate colors of very high fastness. Such a yarn has not been available heretofore.

DYE FORMULATION AMOUNT (parts by weight) Dye A:

Cl Disperse Yellow 42 10 Water 990 Dye B:

CI Disperse Orange 13 20 Water 980 Dye C:

CI Disperse Red 5 Water 995 EXAMPLE 5 A spun yarn of wool (worsted count 40/3; 100% wool) was passed over a heated plate held at 160C at a speed of 700 m/min., and the following three dyes heated to 65C were discharged each at a rate of 16cc/min. from three dye applicator devices, and applied to the surface of the yarn. The yarn was passed through a non-contact heater held at C to dry it,

and wound up. The woundup cheese was formed into a skein, and steamed for minutes at 105C. A weft knitted fabric being of a sprinkled pattern of extreme clearness was produced using the resulting multicolored yarn.

DYE FORMULATIONS AMOUNT (parts by weight) Dye A:

C! Acid Yellow Mi 6 Benzyl Alcohol 60 Ethyl Alcohol 400 Water 534 Dye B:

Cl Acid Orange 56 5 Benzyl Alcohol 60 Ethyl Alcohol 400 Water 535 Dye C:

Cl Acid Red 13] 3 Cl Acid Blue 138 2 Benzyl Alcohol 60 Ethyl Alcohol 400 Water 535 EXAMPLE 6 AMOUNT (parts by weight) DY E FORMULATlONS Dye A:

Cl Basic Yellow I l 6 Ethyl Alcohol 400 Water 594 Dyc B:

Cl Basic Orange 33 I2 Ethyl Alcohol 400 Water 588 Dye C:

Cl Basic Violet 26 I5 Ethyl Alcohol 400 Water 585 EXAMPLE 7 A spun yarn of cotton (cotton count 100 percent cotton) was passed over a heater held at 170C at a speed of 600 m/min., and the following three dyes heated to 65C were discharged at a rate of 8 cc/min., from dye applicators of the type shown in FIG. 2 and applied to the surface of the yarn. The dyed yarn was passed through a non-contact heater held at 140C., dried, and wound-up.

AMOUNT (parts by weight) DYE FORMULATION Dyc A:

Cl Reactive Orange 5 10 Soda Ash l0 Urea 100 Water 880 Dye B:

Cl Reactive Blue 17 Soda Ash l0 5 Urea 100 Water 865 Dye C:

Cl Reactive Black 6 20 Soda Ash l0 Urea I00 Water 870 While the invention has been described in detail and in terms of preferred embodiments thereof it will be apparent that various changes and modifications can be made therein without departing from the spirit and scope thereof.

What is claimed is:

l. A method of continuously dyeing a yarn, which comprises heating a running yarn to a temperature above the boiling point of a solvent in a dye and contacting said heated yarn with one or more dye applicators having a dye discharge aperture while discharging a dye through said aperture and onto said yarn.

2. The method of claim 1, wherein said contacting is with two or more dye applicators sequentially arranged around said yarn in a manner deviating in the advancing direction of said yarn, and wherein said dyes discharged from said dye applicators are the same color or different colors.

3. The method of claim 1, wherein said contacting is with two or more dye applicators sequentially and linearly arranged on the same side of said yarn, and wherein said dye discharged from each of said dye applicators is a different color.

4. The method of claim 1, wherein said dye is discharged continuously.

5. The method of claim 4, wherein a plurality of differently colored dyes is discharged alternately or randomly from the same dye applicator.

6. The method of claim 1, wherein said dye is discharged intermittently.

7. The method of claim 6, wherein said dye is discharged intermittently by incorporating air bubbles in said dye.

8. The method of claim 1, wherein a plurality of differently colored dyes is discharged intermittently from the same dye applicator in an alternate or random manner.

9. The method of claim 1, wherein the temperature of said dye ranges from C below the boiling point of said solvent to the boiling point of said solvent.

10. The method of claim 1, wherein said dye applicator comprises a dye applicator having therein a U- shaped groove through which said running yarn passes in contact therewith and wherein said dye discharge aperture is positioned at the bottom of said U-shaped groove. 

2. The method of claim 1, wherein said contacting is with two or more dye applicators sequentially arranged around said yarn in a manner deviating in the advancing direction of said yarn, and wherein said dyes discharged from said dye applicators are the same color or different colors.
 3. The method of claim 1, wherein said contacting is with two or more dye applicators sequentially and linearly arranged on the same side of said yarn, and wherein said dye discharged from each of said dye applicators is a different color.
 4. The method of claim 1, wherein said dye is discharged continuously.
 5. The method of claim 4, wherein a plurality of differently colored dyes is discharged alternately or randomly from the same dye applicator.
 6. The method of claim 1, wherein said dye is discharged intermittently.
 7. The method of claim 6, wherein said dye is discharged intermittently by incorporating air bubbles in said dye.
 8. The method of claim 1, wherein a plurality of differently colored dyes is discharged intermittently from the same dye applicator in an alternate or random manner.
 9. The method of claim 1, wherein the temperature of said dye ranges from 30*C below the boiling point of said solvent to the boiling point of said solvent.
 10. The method of claim 1, wherein said dye applicator comprises a dye applicator having therein a U-shaped groove through which said running yarn passes in contact therewith and wherein said dye discharge aperture is positioned at the bottom of said U-shaped groove. 